Performance of a multifunctional PV/T hybrid solar window

A building-integrated multifunctional PV/T collector have been developed and evaluated. The PV/T solar window is constructed of PV cells laminated on solar absorbers and is placed in a window behind the glazing. To reduce the costs of the solar electricity, reflectors have been introduced in the construction to focus radiation onto the solar cells. The tiltable reflectors render a possibility to control the amount of radiation transmitted into the building. The insulated reflectors also reduce the thermal losses through the window. A model for simulation of the electric and hot water production was developed. The model can perform yearly energy simulations where different effects such as shading of the cells or effects of the glazing can be included or excluded. The simulation can be run with the reflectors in an active, up right, position or with the reflectors in a passive, horizontal, position. The simulation program was calibrated against measurements on a prototype solar window placed in Lund in the south of Sweden and against a solar window built into a single family house, Solgården, in Älvkarleö in the middle of Sweden. The results from the simulation shows that the solar window produces about 56% more electric energy per unit cell area compared to a vertical flat PV module.